The best way to know is to open the laptop's back panel and check what type of RAM is already installed. In this example, the ...

Rate Lenovo U41-70 Core i5 (5th Gen) - (4 GB DDR3/1 TB HDD/Windows 8/2 GB Graphics) Notebook ...

The laptop features a 14.22 inch display and is powered by a processor. To enhance multi-tasking and fast speed, the company has offered a 4 GB DDR3 and the laptop uses a 320 GB storage.